Fix Brightness Control Not Working for Ubuntu & Linux Mint

Two of the most prominent issues with Ubuntu are brightness control and sound. We saw how to fix no sound issue in an older post. In this quick post, we’ll see how to fix brightness function key not working in Ubuntu.

This article was originally written for Ubuntu 13.10 but it is equally able to fix brightness issue in Ubuntu 14.04, 16.04, 17.10 as well as Linux Mint 17 and 18.

On my Dell Inspiron, using the function key to change the brightness did not yield any results. Brightness was at the maximum and my attempts to lower it went in vain.

It turns out, there are two bugs related to brightness issue in Ubuntu. One relates to Nvidia graphics card and other relates to Intel graphics card. The solution, that worked for me, is for Intel one. Let’s first find out what graphics/video card to do you have.

Step 1: Find video/graphics card in Ubuntu and Linux Mint

Run the command below in the terminal to know what video card is used for the backlight/brightness:

ls /sys/class/backlight/

As you can see, the output for me is dell_backlight and intel_backlight. An indicator that the graphics card in use is Intel. Another way to find out the graphics card would be to go in System Settings->Details->Graphics. You can see the graphics card in use.

About Abhishek Prakash

I am a professional software developer, and founder of It's FOSS. I am an avid Linux lover and open source enthusiast. I use Ubuntu and believe in sharing knowledge. Apart from Linux, I love classic detective mysteries. I'm a huge fan of Agatha Christie's work.